United States Postal Service mailer design regulations that must be followed to ensure safe delivery of your product.

Round Corners - Post Office will not accept or mail any postcards with rounded corners. As it will have issues feeding your product through their sorters.

Standard 4" x 6" Postcard

Standard 4.25" x 5.5" Postcard

Standard 5" x 7" Postcard

Standard 5.5" x 8.5" Postcard

Standard 6" x 11" Jumbo Mailer

Standard 4.15" x 9.5" Envelope

Yellow - Do not put any addresses here with a zip code and state, otherwise there may be a chance of your postcards being returned to you.

Red - No text or graphics are allowed that are greater than 7% grayscale. This is especially important for the Post Office Barcode Area. Unless you print your own mailing barcodes, this area must be kept clear or your postcards will not be mailed or returned to you.